How Healthy Is Coffee?

Most of us start a day with a cup of coffee or tea. It supplies caffeine which is a mild stimulant to the central nervous system that rapidly boosts alertness and energy levels. It has been reported that caffeine is one of the most commonly consumed ingredients in the world. There are studies showing moderate intake can provide a variety of health benefits, including a lower risk of certain cancers, Parkinson’s disease, and liver problems.

Caffeine is a naturally occurring chemical in the seeds, nuts, or leaves of certain plants. It is found in coffee, tea, cola, cocoa, guarana, yerba mate, and many other products. Once consumed, caffeine is quickly absorbed from the intestine into the bloodstream. From there, it reaches the liver and is broken down into compounds that can affect the function of various organs of our body. Having talked about absorption, the main effect of caffeine is on the brain.

Benefits 

Caffeine blocks the effects of adenosine. Adenosine is a neurotransmitter that relaxes the brain and makes us feel tired. Anecdotally, it has been heard that caffeine raises the risk of heart disease but recent research revealed it does not. Instead, studies have shown that drinking 1-4 cups of coffee daily (100-400 mg of caffeine) lowers the risk of heart disease by 16-18 per cent (Wu et al, 2009). Other studies show that drinking 2–4 cups of coffee or green tea per day is linked to a 14–20 per cent lower risk of stroke

Caffeine improves muscle contractions and increases tolerance to fatigue. It may also protect against diabetes. A review noted that those who drink coffee have up to a 29% lower risk of developing type 2 diabetes (Healthline, 2020). Coffee consumption is linked to several other health benefits such as liver protection. Coffee has been shown to reduce the risk of liver damage (cirrhosis) by as much as 84 per cent. It has been shown to slow disease progression, improve treatment response, and lower the risk of premature death (Saab et al, 2013).

Drinking coffee may decrease the risk of premature death by as much as 30 per cent, especially for women and people with diabetes (Lopez-Garcia, 2008). Drinking 2–4 cups of coffee per day may reduce liver cancer risk by up to 64 per cent and colorectal cancer risk by up to 38 per cent (Sang et al, 2013). Consuming 4 or more cups of caffeinated coffee per day may lower the risk of skin cancer by 20 per cent (Loftfield, 2015). In addition, a study linked drinking 2–3 cups of caffeinated coffee (providing about 200–300 mg of caffeine) per day to a 45 per cent lower risk of suicide (Lucas, 2012). Another study reported a 13 per cent lower risk of depression in caffeine consumers (Grosso, 2015).

During exercise, caffeine may alternatively increase the use of fat as a source of energy. This is beneficial during exercise as it can help the glucose stored in muscles last longer, potentially delaying the time it takes our muscles to reach tiredness. Caffeine is rapidly absorbed by the body, and the short-term effects are usually experienced within 30 minutes after having it. These effects range from increased breathing, and heart rate, to increased mental alertness and physical energy. Although varies among individuals, these effects can last up to 12 hours.

However, caffeine consumption carries several risks. Having said it carries risks, consuming too much caffeine can lead to adverse effects. Effects of too much caffeine are a rise in body temperature, frequent urination, dehydration, dizziness and headaches, rapid heartbeat (palpitations), restlessness and excitability, anxiety and irritability, trembling hands, sleeplessness and first feeling energetic but then having an even greater feeling of tiredness and dependency. There are variations among people, some people are more sensitive to the effects while others are not.

For the general population, 400mg (2-4 cups) per day or less is an acceptable dose of caffeine. Caffeine is usually present in many drinks in range from 5-160 mg per 250 ml such as instant coffee: 80–120mg, espresso coffees such as espresso or latte: 105–110mg, chocolate drinks: 5–10mg, black tea: 65–105mg, energy drink: 160mg and Red Bull energy drink: 80mg.  

Caution

Like many other drugs, caffeine is addictive. This means our body becomes used to its effects and needs to take increasing amounts to achieve the same results. Over a period of time, one may become physically and psychologically dependent on caffeine to function effectively. Once a person is dependent on caffeine and stops taking it, he/she may experience withdrawal symptoms. These may include fatigue, crankiness, persistent headache, sweating, muscle pain, and anxiety.

Some people who need to take special care with caffeine include children, pregnant women, and athletes.  For most people, it is not harmful to consume caffeine every day in the form of coffee, tea, or energy drinks. However, it is suggested to drink it without milk and sugar for better health effects.  The bottom line is consuming 2-4 cups of coffee is safe and one can enjoy having it with many beneficial health effects.

(Dr. Lohani is the clinical director at the Nepal Drug and Poison Information Centre. lohanis@gmail.com)